Endoscopic surgical clip applier

ABSTRACT

An endoscopic surgical clip applier includes a handle assembly having a trigger, an endoscopic assembly, a pair of jaw members, a drive bar disposed within the housing of the handle assembly, and a ratchet assembly disposed within the housing of the handle assembly. The drive bar is operatively coupled to the trigger and the pair of jaw members. The ratchet assembly includes a rack disposed on the drive bar, the rack defining a plurality of rack teeth, and a pawl housing slidably mounted within the housing of the handle assembly, the pawl housing having a pawl being selectively engageable with the plurality of rack teeth of the rack, wherein in a first position of the pawl housing, reversal of a direction of movement of the trigger is prohibited, and wherein in a second position of the pawl housing, reversal of the direction of movement of the trigger is permitted.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of and priority to U.S. ProvisionalPatent Application No. 62/453,551 filed Feb. 2, 2017, the entiredisclosure of which is incorporated by reference herein.

BACKGROUND Technical Field

The present disclosure relates generally to surgical clip appliers. Moreparticularly, the present disclosure relates to endoscopic surgical clipappliers having a release switch for a ratchet assembly thereof.

Description of Related Art

Endoscopic surgical staplers and surgical clip appliers are known in theart and are used for a number of distinct and useful surgicalprocedures. Minimally invasive procedures are often generally referredto as endoscopic procedures. Typically, a tube or cannula device isextended into the patient's body through the entrance incision toprovide an access port. The port allows the surgeon to insert a numberof different surgical instruments therethrough using a trocar and forperforming surgical procedures far removed from the incision.

Endoscopic surgical clip appliers having various sizes that areconfigured to apply a variety of diverse surgical clips are known in theart and are capable of applying a single or multiple surgical clipsduring an entry to the body cavity. Such surgical clips are typicallyfabricated from a biocompatible material and are usually compressed overa vessel. Once applied to the vessel, the compressed surgical clipterminates the flow of fluid therethrough.

Endoscopic surgical clip appliers that are able to apply multiple clipsin endoscopic or laparoscopic procedures during a single entry into thebody cavity are described in commonly-assigned U.S. Pat. Nos. 5,084,057and 5,100,420 to Green et al., which are both incorporated by referencein their entirety. Another multiple endoscopic surgical clip applier isdisclosed in commonly-assigned U.S. Pat. No. 5,607,436 by Pratt et al.,the contents of which is also hereby incorporated by reference herein inits entirety. These devices are typically, though not necessarily, usedduring a single surgical procedure.

U.S. Pat. No. 5,695,502 to Pier et al., the disclosure of which ishereby incorporated by reference herein, discloses a resterilizableendoscopic surgical clip applier. The endoscopic surgical clip applieradvances and forms multiple clips during a single insertion into thebody cavity. This resterilizable endoscopic surgical clip applier isconfigured to receive and cooperate with an interchangeable clipmagazine so as to advance and form multiple clips during a single entryinto a body cavity.

During endoscopic procedures it may be desirable and/or necessary topartially form clips, as is necessary, for example, to secure a catheteraround tissue during a cholangiogram or other medical procedures.

Accordingly, a need exists for endoscopic surgical clip appliers thatinclude a release switch for the ratchet assembly. As such, during aclip formation procedure, the clinician can actuate the release switchto reset the ratchet assembly and thus, only partially form a surgicalclip.

SUMMARY

The present disclosure relates to endoscopic surgical clip appliers.

According to an aspect of the present disclosure, an endoscopic surgicalclip applier is provided. The surgical clip applier includes a handleassembly, an endoscopic assembly, a drive bar, and a ratchet assembly.The handle assembly includes a housing, a fixed handle extending fromthe housing, and a trigger pivotally connected to the fixed handle. Theendoscopic assembly is selectively connectable to the housing of thehandle assembly and includes a shaft assembly and a pair of jaw membersoperatively coupled to, and extending from the shaft assembly. The drivebar is disposed within the housing of the handle assembly and isoperatively coupled to the trigger and the pair of jaw members to movethe pair of jaw members between a spaced apart configuration and anapproximated configuration upon actuation of the trigger. The ratchetassembly is disposed within the housing of the handle assembly andincludes a rack disposed on the drive bar, the rack defining a pluralityof rack teeth and having a proximal end and a distal end, and a pawlhousing slidably mounted within the housing of the handle assembly, thepawl housing having a pawl being selectively engageable with theplurality of rack teeth of the rack, wherein in a first position of thepawl housing, the pawl is in registration with the plurality of rackteeth of the rack to prohibit reversal of a direction of movement of thetrigger until the pawl is disposed beyond the proximal end or the distalend of the rack and wherein in a second position of the pawl housing,the pawl is out of registration with the plurality of rack teeth of therack to permit reversal of the direction of movement of the triggerafter an initial engagement of the pawl with the rack.

In one embodiment, the ratchet assembly includes a release switch atleast partially supported within the housing of the handle assembly andoperatively associated with the pawl housing. The release switch isselectively actuatable to move the pawl housing from the first positionthereof to the second portion thereof, wherein in the second position ofthe pawl housing, the pawl housing is moved laterally relative to therack to disengage the pawl from the plurality of rack teeth of the rack.

In one aspect, the pawl housing defines a channel therein, wherein thepawl is located within the channel of the pawl housing.

In embodiments, the ratchet assembly includes a switch pin, wherein thepawl housing defines a central slot therein configured to locate theswitch pin, the switch pin slidably extending through the channel of thepawl housing and the pawl to support the pawl within the channel of thepawl housing.

In some embodiments, the release switch includes a first end cap and asecond end cap, wherein a first side of the housing includes a firstswitch slot configured to slidably receive the first end cap of therelease switch and a second side of the housing includes a second switchslot configured to slidably receive the second end cap of the releaseswitch.

In one embodiment, the first end cap of the release switch is supportedon a first end of the switch pin, on a first side of the pawl housing,and the second end cap of the release switch is supported on a secondend of the switch pin, on a second, opposite side of the pawl housing,such that the release switch is accessible via the first and second endcaps from the first and second sides of the pawl housing, respectively,to actuate the release switch.

In one aspect, the release switch includes a first biasing membersupported on the first end cap and extending between an internal wall ofthe first switch slot and the first side of the pawl housing, and asecond biasing member supported on the second end cap and extendingbetween an internal wall of the second switch slot and the second sideof the pawl housing.

In embodiments, the first biasing member includes a first biasing forceand the second biasing member includes a second biasing force, the firstand second biasing forces configured to cooperate to maintain the pawlhousing in the first position such that the pawl housing is centeredrelative to the rack and the pawl is in registration with the pluralityof rack teeth.

In some embodiments, when the release switch is actuated, by actuatingthe first end cap thereof, the first end cap is moved towards the firstside of the pawl housing such that the first end cap engages the pawlhousing to move the pawl housing to the second position thereof, towardsthe second biasing member, and laterally relative to the rack to movethe pawl out of registration with the plurality of rack teeth.

In one embodiment, when the release switch is actuated, by actuating thesecond end cap thereof, the second end cap is moved towards the secondside of the pawl housing such that the second cap engages the pawlhousing to move the pawl housing to the second position thereof, towardsthe first biasing member, and laterally relative to the rack to move thepawl out of registration with the plurality of rack teeth.

In one aspect, the rack includes a distal clearance and a proximalclearance configured to receive the pawl in an initial and/or a resetposition.

In embodiments, the ratchet assembly includes a pawl spring configuredto bias the pawl into registration with the rack in the first position,wherein in the second position, the pawl spring and at least one of thefirst biasing member and the second biasing member are configured tourge the pawl against a side of the rack until the pawl is locatedwithin the distal clearance or the proximal clearance of the rack.

In some embodiments, when the pawl is located within the distalclearance or the proximal clearance of the rack, at least one of thefirst biasing member and the second biasing member are configured tourge the pawl laterally to the first position thereof, wherein the pawlis centered relative to the rack such that the pawl is in registrationwith the plurality of rack teeth.

In one embodiment, the ratchet assembly includes a distal support pinand a proximal support pin, wherein an outer surface of the pawl housingfurther defines a distal support slot configured for locating the distalsupport pin and a proximal support slot configured for locating theproximal support pin, the distal support pin and the proximal supportpin each coupled to the housing of the handle assembly to slidably mountthe pawl housing within the housing of the handle assembly.

In one aspect, the endoscopic assembly further comprises a plurality ofsurgical clips slidably disposed within the shaft assembly andselectively formable between the pair of jaw members, wherein when thepawl housing is in the first position, the pawl is in registration withthe rack disposed on the drive bar such that upon actuation of thetrigger, the trigger is prevented from reversing the direction ofmovement thereof until the trigger is fully actuated and a distal mostsurgical clip of the plurality of surgical clips is fully formed betweenthe pair of jaw members.

In embodiments, when the pawl housing is in the second position, thepawl is out of registration with the rack disposed on the drive bar suchthat upon partial actuation of the trigger, the trigger is capable ofreversing the direction of movement thereof such that the distal mostsurgical clip of the plurality of surgical clips is partially formedbetween the pair of jaw members.

In some embodiments, the ratchet assembly includes a cover plateprovided on the rack, the cover plate having a pair of wings extendingalong at least a portion of the rack to prevent lateral movement of thepawl housing and disengagement of the pawl from the plurality of rackteeth during a specific portion of the stroke length of the trigger.

According to another aspect of the present disclosure, an endoscopicsurgical clip applier is provided. The surgical clip applier includes ahandle assembly, a shaft assembly extending from the handle assembly, apair of jaw members operatively coupled to, and extending from the shaftassembly, a drive bar, and a ratchet assembly. The handle assemblyincludes a fixed handle and a trigger pivotally connected to the fixedhandle. The drive bar is disposed within the handle assembly and isoperatively coupled to the trigger and the pair of jaws members to movethe pair of jaw members between a spaced apart configuration and anapproximated configuration upon actuation of the trigger. The ratchetassembly is disposed within the handle assembly and includes a rack anda pawl housing. The rack is defined on a top portion of the drive bar,the rack including a plurality of rack teeth and having a proximal endand a distal end. The pawl housing is movably mounted within the handleassembly, the pawl housing having a pawl being selectively engageablewith the plurality of rack teeth of the rack to prohibit, upon actuationof the trigger, a reversal of a direction of movement of the triggeruntil the pawl is disposed beyond the proximal end or the distal end ofthe rack after an initial engagement of the pawl with the rack.

BRIEF DESCRIPTION OF THE DRAWINGS

A particular embodiment of an endoscopic surgical clip applier isdisclosed herein with reference to the drawings wherein:

FIG. 1 is a perspective view of an endoscopic surgical clip applier,according to the present disclosure including an endoscopic assembly anda handle assembly;

FIG. 2A is a perspective view, with parts separated, of the handleassembly of FIG. 1;

FIG. 2B is an enlarged perspective view of the indicated area of detailof FIG. 2A, illustrating a pawl housing and a pawl of the handleassembly of FIG. 1;

FIG. 3 is a perspective view of the handle assembly of FIG. 1 with atleast a housing half-section removed therefrom;

FIG. 4A is a perspective view, of the handle assembly of FIG. 1 with atleast a top housing portion removed or cut away therefrom, illustratinga ratchet assembly thereof;

FIG. 4B is an enlarged perspective view of the indicated area of detailof FIG. 4A, illustrating the ratchet assembly;

FIG. 5 is an enlarged perspective view illustrating the pawl housingincluding the pawl of the ratchet assembly of the handle assembly ofFIG. 1;

FIG. 6 is a cross-sectional, plan view, as taken through 6-6 of FIG. 1,illustrating the ratchet assembly in a first position;

FIG. 7 is a cross-sectional, perspective view illustrating the ratchetassembly in the first position of FIG. 6;

FIG. 8 is a cross-sectional, perspective view illustrating the ratchetassembly in a second position;

FIG. 9 is a cross-sectional, plan view, as taken through 6-6 of FIG. 1,illustrating the ratchet assembly in the second position;

FIG. 10 is a cross-sectional, perspective view of the handle assembly ofFIG. 1 with at least a housing half-section removed therefrom,illustrating the ratchet assembly in the second position and the pawlout of registration with a rack of the ratchet assembly;

FIG. 11 is a cross-sectional, perspective view of the handle assembly ofFIG. 1 with at least a housing half-section removed therefrom,illustrating the ratchet assembly resetting to the first position andthe pawl centered relative to the rack of the ratchet assembly;

FIG. 12 is perspective view of the rack of the ratchet assembly,according to an alternative embodiment of the present disclosure;

FIG. 13 is perspective view of the rack of the ratchet assembly,according to a further alternative embodiment of the present disclosure;and

FIG. 14 is a perspective view of the endoscopic assembly, with partsseparated.

DETAILED DESCRIPTION OF EMBODIMENTS

In accordance with the present disclosure, an endoscopic surgical clipapplier includes a ratchet assembly having a rack, a pawl, and a releaseswitch. In one embodiment, upon actuation of a trigger, the pawl isconfigured to engage a plurality of rack teeth of the rack to prohibitrelease and reversal of a direction of movement of the trigger until thepawl is disposed beyond a proximal end or a distal end of the rack. Inone aspect, the release switch is selectively actuatable to move thepawl out of registration with the plurality of rack teeth of the racksuch that the direction of movement of the trigger may be reversed. Itis contemplated that the release switch may be useful to partially formclips, as is necessary, for example, to secure a catheter around tissueduring a cholangiogram or other medical procedures.

Embodiments of endoscopic surgical clip appliers, in accordance with thepresent disclosure, will now be described in detail with reference tothe drawing figures wherein like reference numerals identify similar oridentical structural elements. As shown in the drawings and describedthroughout the following description, as is traditional when referringto relative positioning on a surgical instrument, the term “proximal”refers to the end of the apparatus which is closer to the user and theterm “distal” refers to the end of the apparatus which is further awayfrom the user.

Referring now to FIGS. 1-14, an endoscopic surgical clip applier inaccordance with an embodiment of the present disclosure, and assembly ina particular configuration, is generally designated as 10. Surgical clipapplier 10 generally includes a handle assembly 100 and an endoscopicassembly 200 that extends distally from handle assembly 100. Generally,endoscopic assembly 200 includes a hub assembly 210, a shaft assembly220 extending from hub assembly 210, and a pair of jaws 250 pivotallyconnected to a distal end of shaft assembly 220. Optionally, at leastone disposable surgical clip cartridge assembly (not shown) may beselectively loadable into shaft assembly 220 of endoscopic assembly 200.

Referring now to FIGS. 1-2B, handle assembly 100 of surgical clipapplier 10 is shown and will be described. Handle assembly 100 includesa housing 102 having a first or right side half-section 102 a and asecond or left side half-section 102 b. Housing 102 of handle assembly100 further includes or defines a nose 102 c for supporting hub assembly210 of endoscopic assembly 200, and a fixed handle 102 d.

Housing 102 of handle assembly 100 may be formed of a suitable plasticor thermoplastic material. It is further contemplated that housing 102of handle assembly 100 may be fabricated from stainless steel or thelike.

Handle assembly 100 includes a trigger 104 pivotably supported betweenright side half-section 102 a and left side half-section 102 b ofhousing 102. Trigger 104 is pivotably movable in a first direction suchthat the trigger 104 and the fixed handle 102 d are approximated andpivotably movable in a second, opposite, direction such that the trigger104 and the fixed handle 102 d are spaced-apart.

A drive bar 106 is supported within the housing 102 of the handleassembly 100. The drive bar 106 is operatively coupled to the trigger104 and the pair of jaws 250 to move the pair of jaws between aspaced-apart configuration and an approximated configuration uponactuation of the trigger 104. Specifically, the handle assembly 100includes a wishbone link 108 configured to couple the trigger 104 andthe drive bar 106. Wishbone link 108 includes a first end having a tail108 a and a second end having a first arm and a second arm 108 b, 108 cspaced-apart to define a space 108 d therebetween. The tail 108 a of thewishbone link 108 is pivotably connected to the trigger 104 through atrigger slot 104 a. Specifically, tail 108 a of wishbone link 108includes an opening 108 f configured for pivotably locating a pin 104 bdefined within trigger slot 104 a. The space 108 d between the first andsecond arms 108 b, 108 c is configured to receive the drive bar 106. Thefirst and second arms 108 b, 108 c of wishbone link 108, and the drivebar 106 includes corresponding apertures 108 e, 106 c, respectively,configured to locate a drive bar pin 110 to pivotably connect thewishbone link 108 and the drive bar 106. The wishbone link 108 isconfigured to translate the pivotal movement of the trigger 104 intolongitudinal movement of the drive bar 106, as will be detailed below.

In one embodiment, the drive bar 106 is a substantially flat memberhaving a distal end portion 106 a and a proximal end 106 b. Generally,distal end portion 106 a of drive bar 106 includes an hook member 114that is provided to mate with a feature of endoscopic assembly 200. Assuch, drive bar 106 is configured to move one or more driving structuresto load, and actuate the pair of jaws 250 to form a fully formed orpartially formed clip, and then reset to an initial position for thenext clip application. A biasing member, such as, for example, a returnspring 112 is disposed to surround the drive bar 106 adjacent the distalend portion 106 a. After the trigger 104 is actuated and the wishbonelink 108 advances the drive bar 106 in a longitudinal or distal manner,the return spring 112 is provided to return the drive bar 106 and thetrigger 104 to its original position for the next clip application.

With additional reference to FIGS. 3-5, surgical clip applier 10includes a ratchet assembly 300 disposed within housing 102 of handleassembly 100. The ratchet assembly 300 includes a rack 310, a pawlhousing 320 having a pawl 330 disposed therein, and a release switch 340at least partially supported within housing 102 of handle assembly 100.

As shown in FIG. 3, the rack 310 is supported by or is provided on a topsurface 106 d of the drive bar 106 and includes a distal portion 310 aand a proximal portion 310 b. The rack 310 defines a plurality of rackteeth 312 in series between the distal portion 310 a and the proximalportion 310 b. The rack 310 also includes a distal clearance or well 314a located adjacent the distal end 310 a and a proximal clearance or well314 b located adjacent the proximal end 310 b of the rack 310. Thedistal well 314 a and the proximal well 314 b are configured to receivethe pawl 330 in an initial and/or reset position, as will be detailedfurther.

A shown in FIG. 4B, the pawl housing 320 is slidably mounted within thehandle assembly 100 between the right side half-section 102 a and theleft side half-section 102 b of the housing 102. Specifically, theratchet assembly 300 includes a distal support pin 302 a and a proximalsupport pin 302 b and the pawl housing 320 includes a distal supportslot 322 a and a proximal support slot 322 b configured to locate thedistal support pin 302 a and the proximal support pin 302 b,respectively. The distal support pin 302 a and the proximal support pin302 b are mounted onto a plurality of corresponding slots 103 a withinthe housing 102 to slidably mount the pawl housing 320 within thehousing 102 of the handle assembly 100. In embodiments, as bestillustrated in FIG. 5, pawl housing 320 further includes a first guidechannel 323 a and a second guide channel 323 b configured for locating afirst guide feature 103 b and a second guide feature 103 c,respectively, extending from at least one of the right side half-section102 a or the left side half-section 102 b of housing 102. It iscontemplated that the first and second guide features 103 b, 103 c areprovided to align the distal and proximal support slots 322 a, 322 b ofthe pawl housing 320 with the plurality of corresponding slots 103 a ofhousing 102 for locating the distal and proximal support pins 302 a, 302b, respectively.

As shown in FIGS. 2B and 5, the pawl housing 320 further defines achannel or recess 324 configured to locate the pawl 330 therein. Pawl330 is pivotably connected to the pawl housing 320 by a switch pin 332at a location wherein pawl 330 is in substantial operative engagementwith the rack 310. The switch pin 332 extends through a central slot 326defined in the pawl housing 320 and a corresponding slot 334 defined inthe pawl 330. The ratchet assembly 300 further includes a pawl spring336 disposed within the pawl housing 320 and configured to verticallybias pawl 330 into operative engagement with the rack 310. Specifically,the pawl spring 336 includes a distal hook 336 a configured to latchonto the distal support pin 302 a and a proximal hook 336 b configuredto latch onto the proximal support pin 302 b. It is contemplated thatpawl spring 336 is positioned in a manner configured to maintain a pawltooth 338 of the pawl 330 in engagement with the plurality of rack teeth312, as well as to maintain the pawl 330 in a rotated or cantedposition.

Referring now to FIG. 6, in a first position, the pawl 330 is engagablewith the rack 310 to restrict longitudinal movement of rack 310 and, inturn, trigger 104. In use, as trigger 104 is actuated (from a fullyun-actuated position), rack 310 is also moved into engagement with pawl330. Rack 310 has a length which allows pawl 330 to reverse and advanceback over rack 310, when rack 310 changes between proximal or distalmovement (after pawl tooth 338 enters distal clearance 314 a), astrigger 104 reaches a fully actuated or fully un-actuated position. Therelative lengths and sizes of rack 310 of ratchet assembly 300, trigger104 and drive bar 106 define a stroke length of trigger 104, drive bar106 or handle assembly 100.

Ratchet assembly 300 further includes release switch 340 at leastpartially supported within housing 102 of handle assembly 100. Releaseswitch 340 is operatively associated with pawl housing 320 and isoperable to selectively move pawl housing 320, and in turn pawl 330,into or out of registration with the plurality of rack teeth 312 of rack310.

In this manner, when pawl 330 is moved to a second position, out ofregistration with the plurality of rack teeth 312 of rack 310 (see FIG.9), trigger 104 is free to open and close as needed due to pawl 330having no blocking effect on rack 310 of ratchet assembly 300. As such,trigger 104 may be partially actuated (without having to be fullyactuated), and may be returnable to a fully un-actuated position. Such afeature permits a user to partially squeeze or actuate trigger 104 forperforming a cholangiogram procedure or the like.

With reference to FIG. 6, release switch 340 includes a first end cap342 a slidably supported on a first end portion 332 a of switch pin 332and a second end cap 342 b slidably supported on a second end portion332 b of switch pin 332.

First end cap 342 a has a first extension 343 a and defines asubstantially “T” shaped profile. First end cap 342 a defines a firstchannel or bore 345 a therethrough, sized and configured to slidablyreceive the first end portion 332 a of switch pin 332. Similarly, secondend cap 342 b has a second extension 343 b and defines a substantially“T” shaped profile. Second end cap 342 b defines a second channel orbore 345 b therethrough, sized and configured to slidably receive thesecond end portion 332 b of switch pin 332.

In one embodiment, first and second end caps 342 a, 342 b arecylindrically shaped, each including a first diameter “D1”. Similarly,in one embodiment, first and second extensions 343 a, 343 b arecylindrically shaped, each including a second diameter “D2” that is lessthan the first diameter “D1”. Alternatively, first and second end caps342 a, 342 b and first and second extensions 343 a, 343 b, respectively,may include various shapes and sizes as necessary for its intendedpurpose.

Right side half-section 102 a of housing 102 includes a first switchslot or bore 105 sized and configured to slidably receive the first endcap 342 a and left side half-section 102 b of housing 102 includes asecond switch slot or bore 107 sized and configured to slidably receivethe second end cap 342 b. Once first and second end caps 342 a, 342 bare received within first and second switch slots 105, 107,respectively, first and second extensions 343 a, 343 b are provided tobe in contact with a first side 328 a and a second side 328 b of pawlhousing 320, respectively.

In one embodiment, first and second switch slots 105, 107 each include afirst portion 105 a, 107 a, respectively, defining a third diameter “D3”that is slightly larger than the first diameters “D1” of first andsecond end caps 342 a, 342 b to enable slidable insertion of first andsecond end caps 342 a, 342 b into first portions 105 a, 107 a withoutsignificant play or clearance therebetween. First and second switchslots 105, 107 each further include an internal wall 105 b, 107 b.Internal walls 105 b, 107 b are provided to prevent slidable insertionof first and second end caps 342 a, 342 b beyond first portions 105 a,107 a, respectively. Internal walls 105 b, 107 b each define an opening105 c, 107 c, respectively, defining a fourth diameter “D4” that is lessthan the third diameter “D3” of first portions 105 a, 107 a. The fourthdiameter “D4” of each opening 105 c, 107 c is slightly larger than thesecond diameters “D2” of the first and second extensions 343 a, 343 b toenable slidable insertion of the first and second extensions 343 a, 343b into the openings 105 c, 107 c without significant play or clearancetherebetween.

First and second end caps 342 a, 342 b project from first and secondswitch slots 105, 107, respectively, and may be actuated by a finger ofa user to actuate release switch 340. It is contemplated that firstportions 105 a, 107 a, of first and second switch slots 105, 107,respectively, provide sufficient runway to enable first and second endcaps 342 a, 342 b, respectively, to move therethrough to actuate releaseswitch 340.

In one embodiment, housing 102 of handle assembly 100 may be providedwith guard walls (not specifically shown) surrounding the first andsecond end caps 342 a, 342 b in order to inhibit inadvertent actuationof release switch 340. In some embodiments, the first and second endcaps 342 a, 342 b may be flush with an outer surface of housing 102 ofhandle assembly 100 in order to also inhibit inadvertent actuation ofrelease switch 340.

Release switch 340 is movable, upon actuation of first or second endcaps 342 a, 342 b, between the first position (noted above; see FIGS. 3,6, and 7) in which ratchet assembly 300 is “on” or “activated” such thatpawl 330 is in or moved into operative engagement/registration with theplurality of rack teeth 312, thereby enabling or re-enabling theoperability of ratchet assembly 300, and the second position (notedabove; see FIGS. 8-10) in which ratchet assembly 300 is “off” or“de-activated” such that pawl 330 is out of or moved out of operativeengagement/registration with the plurality of rack teeth 312.

It is contemplated that release switch 340, and in turn ratchet assembly300, default to the first position, in which pawl 330 is engaged with/inregistration with the plurality of rack teeth 312. To that end, releaseswitch 340 includes a first biasing member 344 supported on firstextension 343 a of first end cap 343 a, extending between a first side328 a of pawl housing 320 and internal wall 105 b of first switch slot105, and includes a second biasing member 346 supported on secondextension 343 b of second end cap 342 b, extending between a second side328 b of pawl housing 320 and internal wall 107 b of second switch slot107. The first biasing member 344 includes a first biasing force “BF1”and is provided to bias or urge second end cap 342 b away from internalwall 107 b of second switch slot 107. Similarly, the second biasingmember 346 includes a second biasing force “BF2” and is provided to biasor urge first end cap 342 a away from internal wall 105 b of firstswitch slot 105. Together, first and second biasing members 344, 346cooperate to maintain pawl housing 320 in the first position such thatpawl housing 320 is centered relative to rack 310 (see FIG. 6) and thepawl 330 is engagable with the rack 310 to restrict longitudinalmovement of rack 310.

As noted above, release switch 340 is actuatable from the first positiontowards the second position, upon actuation of the first or second endcaps 342 a, 342 b. Accordingly, for illustrative purposes, the use ofrelease switch 340 will be detailed with reference to actuation of thefirst end cap 342 a.

Referring now to FIGS. 6-11, in use, when release switch 340 is actuatedtowards the second position by moving or depressing first end cap 342 alaterally towards the first side 328 a of the pawl housing 320, firstextension 343 a of first end cap 343 a engages first side 328 a of pawlhousing 320 to move pawl housing 320 towards second biasing member 346and pawl 330 out of operative engagement/registration with the pluralityof rack teeth 312 of rack 310. The movement of pawl housing 320 towardssecond biasing member 346, compresses second biasing member 346 betweensecond side 328 b of pawl housing 320 and internal wall 107 b of secondswitch slot 107.

As noted above, pawl housing 320 includes a pawl spring 336 disposedtherein and configured to vertically bias pawl 330. In the firstposition, pawl spring 336 vertically biases pawl 330 into operativeengagement with the rack 310. In the second position, when pawl 330 ismoved out of operative engagement/registration with the plurality ofrack teeth 312 and abuts a side of rack 310, the combined biases of pawlspring 336 and second biasing member 346 acts on pawl 330 such that pawl330 is wedged or held against the side of rack 310 (see FIG. 9) anddisengaged from plurality of rack teeth 312 until rack 310 is movedproximally (see FIG. 10) such that pawl 330 is located within distalwell 314 a (see FIG. 11) or until rack 310 is moved distally such thatpawl 330 is located within proximal well 314 b. When pawl 330 is locatedwithin distal well 314 a or proximal well 314 b, second biasing member346 is permitted to expand (without being impeded by the side of rack310) such that second biasing force “BF2” acts on pawl housing 320 tomove pawl housing 320 laterally back towards the first position whereinpawl 330 is centered relative to rack 310 such that pawl 330 isengagable with the plurality of rack teeth 312 of rack 310 upon furtherlongitudinal movement of rack 310, thereby enabling or re-enabling theoperability of ratchet assembly 300.

With brief reference to FIGS. 12 and 13, in embodiments, rack 310 mayinclude features to prevent actuation of release switch 340 towards thesecond position during a specific portion of the stroke length oftrigger 104. These features may be advantageous to prevent aninadvertent return of trigger 104 once a clip has been fully formed orpartially formed but has not been fired from surgical clip applier 10.These features may also be advantageous to prevent inadvertent doubleloading of a clip into the pair of jaws 250.

In one embodiment, as illustrated in FIG. 12, rack 310 may include acover plate 350 disposed thereon. Cover plate 350 includes a channel 352through which the plurality of rack teeth 312 of rack 310 are accessiblewhen cover plate 350 is disposed on rack 310. Cover plate 350 includes apair of wings or walls 354 a, 354 b extending from opposing sides ofchannel 352 and towards pawl housing 320. The pair of wings 354 a, 354 bextend along at least a portion of a length of rack 310 to preventlateral movement of pawl housing 320 and disengagement of pawl 330 fromthe plurality of rack teeth 312 during a specific portion of the strokelength of trigger 104.

In one embodiment, as illustrated in FIG. 13, rack 310 may insteadinclude a pair of plates 360 a, 360 b affixed to opposite sides of rack310. The pair of plates 360 a, 360 b extends from the opposite sides ofrack 310 and towards pawl housing 320 to define a pair of shoulders orwalls 362 a, 362 b on opposing sides of the plurality of rack teeth 312.The pair of shoulders 362 a, 362 b extends along at least a portion of alength of rack 310 to prevent lateral movement of pawl housing 320 anddisengagement of pawl 330 from the plurality of rack teeth 312 during aspecific portion of the stroke length of trigger 104.

As noted above, and illustrated in FIG. 14, surgical clip applier 10includes an endoscopic assembly 200 having hub assembly 210, shaftassembly 220, and the pair of jaws 250. Hub assembly 210 is rotatablymounted on nose 102 c (see FIG. 2A) of housing 102 of handle assembly100 and is connected to a proximal end portion of shaft assembly 220 toprovide a three hundred sixty degree rotation of the shaft assembly 220and the pair of jaws 250 thereon relative to a longitudinal center axisof shaft assembly 220. Hub assembly 210 has a suitable configuration soas to be rotated simply using a clinician's finger.

Endoscopic assembly 200 includes a spindle link 260 for operativelyconnecting drive bar 106 to a driving mechanism 400 to move the pair ofjaws 250 between the spaced-apart configuration and the approximatedconfiguration upon actuation of trigger 104. Specifically, hook member114 (see FIG. 3) of drive bar 106 is coupled to a first end 260 a ofspindle link 260 and a spindle 270 of drive mechanism 400 is coupled toa second end 260 b of spindle link 260. In this manner, translation ofdrive bar 106 in a distal and proximal direction can thus advance andretract spindle 270, respectively.

Drive mechanism 400 further includes an elongated clip channel member280 for retaining a number of surgical clips 290 shown in an alignedmanner above the clip channel member 280. A clip follower 282 and a clipfollower spring 284 are provided to urge the surgical clips 290 distallythrough the elongated clip channel member 280. A channel cover 286 isprovided to overlay the elongated clip channel member 280 and retain andguide the clip follower 282 and clip follower spring 284 and thesurgical clips 290 distally in the elongated clip channel member 280.

Drive mechanism 400 also has a feed bar 410 for feeding the surgicalclips 290 between the pair of jaws 250. Drive mechanism 400 alsoincludes a filler component 420 and a wedge plate 430.

For a more detailed description of the construction and operation ofendoscopic assembly 200, reference may be made to U.S. Pat. No.7,637,917, the entire content of which is incorporated herein byreference.

It should be understood that the foregoing description is onlyillustrative of the present disclosure. Various alternatives andmodifications can be devised by those skilled in the art withoutdeparting from the disclosure. Accordingly, the present disclosure isintended to embrace all such alternatives, modifications and variances.The embodiments described with reference to the attached drawing figuresare presented only to demonstrate certain examples of the disclosure.Other elements, steps, methods and techniques that are insubstantiallydifferent from those described above and/or in the appended claims arealso intended to be within the scope of the disclosure.

What is claimed is:
 1. An endoscopic surgical clip applier, comprising:a handle assembly including: a housing; a fixed handle extending fromthe housing; and a trigger pivotally connected to the fixed handle; anendoscopic assembly selectively connectable to the housing of the handleassembly, the endoscopic assembly including: a shaft assembly; and apair of jaw members operatively coupled to, and extending from the shaftassembly; a drive bar disposed within the housing of the handle assemblyand operatively coupled to the trigger and the pair of jaw members tomove the pair of jaw members between a spaced apart configuration and anapproximated configuration upon actuation of the trigger; a ratchetassembly disposed within the housing of the handle assembly, the ratchetassembly including: a rack disposed on the drive bar, the rack defininga plurality of rack teeth and having a proximal end and a distal end;and a pawl housing slidably mounted within the housing of the handleassembly, the pawl housing having a pawl being selectively engageablewith the plurality of rack teeth of the rack, wherein in a firstposition of the pawl housing, the pawl is in registration with theplurality of rack teeth of the rack to prohibit reversal of a directionof movement of the trigger until the pawl is disposed beyond theproximal end or the distal end of the rack and wherein in a secondposition of the pawl housing, the pawl is out of registration with theplurality of rack teeth of the rack to permit reversal of the directionof movement of the trigger after an initial engagement of the pawl withthe rack.
 2. The endoscopic surgical clip applier according to claim 1,wherein the ratchet assembly includes a release switch at leastpartially supported within the housing of the handle assembly andoperatively associated with the pawl housing, the release switchselectively actuatable to move the pawl housing from the first positionthereof to the second portion thereof, wherein in the second position ofthe pawl housing, the pawl housing is moved laterally relative to therack to disengage the pawl from the plurality of rack teeth of the rack.3. The endoscopic surgical clip applier according to claim 1, whereinthe pawl housing defines a channel therein, and wherein the pawl islocated within the channel of the pawl housing.
 4. The endoscopicsurgical clip applier according to claim 3, wherein the ratchet assemblyincludes a switch pin, wherein the pawl housing defines a central slottherein configured to locate the switch pin, the switch pin slidablyextending through the channel of the pawl housing and the pawl tosupport the pawl within the channel of the pawl housing.
 5. Theendoscopic surgical clip applier according to claim 4, wherein therelease switch includes a first end cap and a second end cap, wherein afirst side of the housing includes a first switch slot configured toslidably receive the first end cap of the release switch and a secondside of the housing includes a second switch slot configured to slidablyreceive the second end cap of the release switch.
 6. The endoscopicsurgical clip applier according to claim 5, wherein the first end cap ofthe release switch is supported on a first end of the switch pin, on afirst side of the pawl housing, and the second end cap of the releaseswitch is supported on a second end of the switch pin, on a second,opposite side of the pawl housing, such that the release switch isaccessible via the first and second end caps from the first and secondsides of the pawl housing, respectively, to actuate the release switch.7. The endoscopic surgical clip applier according to claim 4, whereinthe release switch includes: a first biasing member supported on thefirst end cap and extending between an internal wall of the first switchslot and the first side of the pawl housing; and a second biasing membersupported on the second end cap and extending between an internal wallof the second switch slot and the second side of the pawl housing. 8.The endoscopic surgical clip applier according to claim 7, wherein thefirst biasing member includes a first biasing force and the secondbiasing member includes a second biasing force, the first and secondbiasing forces configured to cooperate to maintain the pawl housing inthe first position such that the pawl housing is centered relative tothe rack and the pawl is in registration with the plurality of rackteeth.
 9. The endoscopic surgical clip applier according to claim 8,wherein when the release switch is actuated, by actuating the first endcap thereof, the first end cap is moved towards the first side of thepawl housing such that the first end cap engages the pawl housing tomove the pawl housing to the second position thereof, towards the secondbiasing member, and laterally relative to the rack to move the pawl outof registration with the plurality of rack teeth.
 10. The endoscopicsurgical clip applier according to claim 8, wherein when the releaseswitch is actuated, by actuating the second end cap thereof, the secondend cap is moved towards the second side of the pawl housing such thatthe second cap engages the pawl housing to move the pawl housing to thesecond position thereof, towards the first biasing member, and laterallyrelative to the rack to move the pawl out of registration with theplurality of rack teeth.
 11. The endoscopic surgical clip applieraccording to claim 7, wherein the rack includes a distal clearance and aproximal clearance configured to receive the pawl in an initial and/or areset position.
 12. The endoscopic surgical clip applier according toclaim 11, wherein the ratchet assembly includes a pawl spring configuredto bias the pawl into registration with the rack in the first position,wherein in the second position, the pawl spring and at least one of thefirst biasing member and the second biasing member are configured tourge the pawl against a side of the rack until the pawl is locatedwithin the distal clearance or the proximal clearance of the rack. 13.The endoscopic surgical clip applier according to claim 12, wherein whenthe pawl is located within the distal clearance or the proximalclearance of the rack, at least one of the first biasing member and thesecond biasing member are configured to urge the pawl laterally to thefirst position thereof, wherein the pawl is centered relative to therack such that the pawl is in registration with the plurality of rackteeth.
 14. The endoscopic surgical clip applier according to claim 1,wherein the ratchet assembly includes a distal support pin and aproximal support pin, wherein an outer surface of the pawl housingfurther defines a distal support slot configured for locating the distalsupport pin and a proximal support slot configured for locating theproximal support pin, the distal support pin and the proximal supportpin each coupled to the housing of the handle assembly to slidably mountthe pawl housing within the housing of the handle assembly.
 15. Theendoscopic surgical clip applier according to claim 1, wherein theendoscopic assembly further comprises a plurality of surgical clipsslidably disposed within the shaft assembly and selectively formablebetween the pair of jaw members, wherein when the pawl housing is in thefirst position, the pawl is in registration with the rack disposed onthe drive bar such that upon actuation of the trigger, the trigger isprevented from reversing the direction of movement thereof until thetrigger is fully actuated and a distal most surgical clip of theplurality of surgical clips is fully formed between the pair of jawmembers.
 16. The endoscopic surgical clip applier according to claim 15,wherein when the pawl housing is in the second position, the pawl is outof registration with the rack disposed on the drive bar such that uponpartial actuation of the trigger, the trigger is capable of reversingthe direction of movement thereof such that the distal most surgicalclip of the plurality of surgical clips is partially formed between thepair of jaw members.
 17. The endoscopic surgical clip applier accordingto claim 1, wherein the ratchet assembly includes a cover plate providedon the rack, the cover plate having a pair of wings extending along atleast a portion of the rack to prevent lateral movement of the pawlhousing and disengagement of the pawl from the plurality of rack teethduring a specific portion of the stroke length of the trigger.
 18. Anendoscopic surgical clip applier, comprising: a handle assemblyincluding: a fixed handle; and a trigger pivotally connected to thefixed handle; a shaft assembly extending from the handle assembly; apair of jaw members operatively coupled to, and extending from the shaftassembly; a drive bar disposed within the handle assembly andoperatively coupled to the trigger and the pair of jaw members to movethe pair of jaw members between a spaced apart configuration and anapproximated configuration upon actuation of the trigger; a ratchetassembly disposed within the handle assembly, the ratchet assemblyincluding: a rack defined on a top portion of the drive bar, the rackincluding a plurality of rack teeth and having a proximal end and adistal end; and a pawl housing movably mounted within the handleassembly, the pawl housing having a pawl being selectively engageablewith the plurality of rack teeth of the rack to prohibit, upon actuationof the trigger, a reversal of a direction of movement of the triggeruntil the pawl is disposed beyond the proximal end or the distal end ofthe rack after an initial engagement of the pawl with the rack.
 19. Theendoscopic surgical clip applier according to claim 18, wherein theratchet assembly includes a release switch operatively associated withthe pawl housing and selectively actuatable to move the pawl housinglaterally relative to the rack to move the pawl out of registration withthe plurality of rack teeth of the rack, such that upon actuation of thetrigger, the direction of movement of the trigger is not reversiblebefore the pawl is disposed beyond the proximal end or the distal end ofthe rack to enable partial actuation of the trigger.
 20. The endoscopicsurgical clip applier according to claim 18, further comprising asurgical clip slidably disposed within the shaft assembly andselectively formable between the pair of jaws, wherein when the pawl isin registration with the rack disposed on the drive bar and the triggeris actuated, the trigger is prevented from reversing the direction ofmovement thereof until the trigger is fully actuated such that thesurgical clip is fully formed between the pair of jaw members.
 21. Theendoscopic surgical clip applier according to claim 19, wherein when therelease switch is actuated such that the pawl is out of registrationwith the rack disposed on the drive bar, the trigger is partiallyactuatable such that the surgical clip is partially formed between thepair of jaw members.